Disclosed are systems and devices for controlling the closing of a door. A head unit is to be installed in a doorjamb, comprising a chamber filled at least in part with a shear thickening fluid. A piston is connected to a cap and configured to exert pressure against the shear thickening fluid in response to a force applied to the cap. The systems and devices provide an adjustable design that resists door slamming and aggressive closure, serving as a safety device as well as noise, damage and pet control around doors (preventing closure if desired). An install kit provides exact location, depth control and guide to place over the head unit to tap it into place with a hammer.

A double eccentric positioning apparatus uses two equal offset eccentric bushings to accurately position a tool (such as a drill bushing) in two dimensions. Miniature servo motors and precise gearing control the rotation of each eccentric bushing, which controls the direction of the offset vectors. The offset vectors are used to determine the final position of the drill bushing. The desired rotation angles can be mathematically calculated based on desired position. The inner eccentric bushing is located concentric to the offset of the outer eccentric bushing. This allows any position, within a radius of two times the eccentric offset, to be achieved. The use of worm gearing on the eccentric bushings prevents back-driving of the servo motors, due to the lead angle of the worm gears, and the friction between the worm wheel and worm gear.

Drilling aid apparatuses and methods for drilling a structure are provided. In one example, a drilling aid apparatus includes a bushing holder portion. The bushing holder portion has a first surface for facing a first structure portion, a second surface on a side opposite the first surface, and an opening formed through the bushing holder portion extending from the first surface to the second surface. The opening is configured to receive a bushing that is sized for guiding a drill bit for drilling into the first structure portion. A first coupling member is coupled to the bushing holder portion and is configured to couple to a second structure portion for supporting the bushing holder portion in a fixed position relative to the first structure portion.

A machining tool assembly is provided for machining a blank to form a firearm lower receiver. The assembly includes a pair of side plates positionable on opposed sides of the blank to capture the blank therebetween. A template plate having a template aperture is adapted to be removeably attachable to the side plates. The template aperture is aligned with a top surface of the blank and is adapted for machining a cavity within the blank having a peripheral contour complimentary to a peripheral contour of the template aperture. A centering mechanism is adapted to be removeably attachable to the template plate, with the centering mechanism including an opening aligned with a corresponding void formed on the blank to align the blank with the template plate.

A colleted bushing includes a collet and a bushing. The collet has a collet proximal end and a collet bore having collet threads. In addition, the collet has a collet bore taper located adjacent the collet proximal end, and a plurality of collet fingers located adjacent the collet proximal end and configured to be inserted into a workpiece hole of a workpiece. The bushing has a bushing proximal end, a bushing bore, a bushing outer surface, and bushing threads formed along a section of the bushing outer surface. The bushing is configured to be inserted into the collet bore and the bushing threads are configured to engage the collet threads in a manner resulting in movement of the bushing proximal end into contact with the collet bore taper causing the collet fingers to be urged radially outwardly and removably locking the collet within the workpiece hole.

A guide device comprising a hollow body configured to receive a drill bit, the hollow body having a first end; a second end; and a continuous section intermediate the first end and the second end; an opening extending from the first end through the continuous section to the second end; and at least one aperture located on the hollow body intermediate the first and second end of the hollow body.

According to one implementation, a drill includes: a drill includes: a body without a back taper; and a cutting edge part integrated with the body. The body has a flow path of a cutting oil inside. The cuffing edge part has a first supply port that supplies the cutting oil toward a workpiece, The body has at least one second supply port that supplies the cutting oil to a clearance formed between a bush for positioning and the body. The bush is used by being inserted in the body.

The reusable liquid metal castable drill bushing assembly for use in a fixture plate includes a cylindrical sleeve having an inner diameter, a cylindrical drill bushing having an outer diameter, a liquid metal disposed between the outer diameter of the cylindrical drill hushing and the inner diameter of the cylindrical sleeve, a seal disposed on the cylindrical sleeve, the cylindrical drill bushing, and the liquid metal such that the seal retains the liquid metal between the outer diameter of the cylindrical drill bushing and the inner diameter of the cylindrical sleeve.

A system for transferring a hole pattern from a first component to a second component configured to couple to the first component is provided including a contour plate having a drill plate with a hole pattern substantially identical to the hole pattern of the first component. The position of the drill plate is adjustable to match the hole pattern of the drill plate with the hole pattern of the first component. A slidable fixture configured to support the second component is movable to align the second component with the drill plate such that the hole pattern of the drill plate in relation to the second component matches the hole pattern of the drill plate in relation to the hole pattern of the first component. The hole pattern of the drill plate is used to create a hole pattern in the second component matching the hole pattern of the first component.